title: Accuracy and false-positive rate of the cytologic diagnosis of follicular cervicitis: observations from the College of American Pathologists Pap Educational Program.
abstract: BACKGROUND
  Follicular cervicitis is usually easily identifiable on Papanicolaou (Pap) tests; however, historically, follicular cervicitis is reported to lead to false-positive diagnoses of epithelial cell abnormalities.
  
  
  OBJECTIVE
  To assess participant responses in the College of American Pathologists (CAP) Pap educational program (CAP-PAP) to determine the accuracy and false-positive rate of follicular cervicitis cases. Design.-We performed a retrospective review of 4914 participant responses for gynecologic cytology challenges with the reference diagnosis of follicular cervicitis during 11 years (2000-2010) from CAP-PAP. Reference diagnosis category, false-positive rates by participant type (laboratory, cytotechnologist, pathologist), and preparation type (conventional smears, ThinPrep) were analyzed.
  
  
  RESULTS
  Of the total 4914 general category responses, 4368 (88.9%) were benign while 546 (11.1%) responses were epithelial cell abnormalities (false positives). Of benign responses, only 2026 (46.4%) were an exact match to follicular cervicitis. Adenocarcinoma and high-grade squamous intraepithelial lesion were the most common diagnoses chosen as a false-positive interpretation (42.3% and 20.1%, respectively). Participant type was significantly associated with false-positive interpretations (laboratory: 19.2%; cytotechnologist: 11.1%; pathologist: 7.9%; P < .001). ThinPrep was also significantly associated with false-positive results as compared to conventional smears (12.2% versus 3.6%; P < .001).
  
  
  CONCLUSIONS
  In an interlaboratory comparison educational program, follicular cervicitis is difficult to interpret accurately and represents an important cause of false-positive responses. Follicular cervicitis may mimic adenocarcinoma or high-grade squamous intraepithelial lesion, particularly in liquid-based preparations. The diagnostic difficulty most likely arises from the lymphocytes being less conspicuous in the background as well as their tendency to aggregate in ThinPrep as compared to conventional smears.
authors.affiliation: Department of Pathology, McGill University and McGill University Health Center, Montreal, Quebec H3A 2B4, Canada.
authors.forename: Manon
authors.initials: M
authors.lastname: Auger
authors.forename: Walid
authors.initials: W
authors.lastname: Khalbuss
authors.forename: Ritu
authors.initials: R
authors.lastname: Nayar
authors.forename: Chengquan
authors.initials: C
authors.lastname: Zhao
authors.forename: Patricia
authors.initials: P
authors.lastname: Wasserman
authors.forename: Rhona
authors.initials: R
authors.lastname: Souers
authors.forename: Nicole
authors.initials: N
authors.lastname: Thomas
authors.forename: Ann T
authors.initials: AT
authors.lastname: Moriarty
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis / Q000453:epidemiology; D002170:Canada / Q000453:epidemiology; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis / Q000453:epidemiology; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D065006:Papanicolaou Test; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012955:Societies, Medical; D014481:United States / Q000453:epidemiology; D002583:Uterine Cervical Neoplasms / Q000175:diagnosis* / Q000453:epidemiology; D002575:Uterine Cervicitis / Q000175:diagnosis* / Q000453:epidemiology; D014626:Vaginal Smears / Q000379:methods / Q000592:standards*; D002578:Uterine Cervical Dysplasia / Q000175:diagnosis / Q000453:epidemiology